You'll loose a lot of information when you export the spread sheet as a csv file. It all depends on what's in the spread sheet and what you wan't to do with it on the other end. Exporting to csv reduces the file size but it is not a "universal" answer. Compressing the spread sheet into a zip file will reduce the size for transmission without loosing any information.

You'll loose a lot of information when you export the spread sheet as a csv file. It all depends on what's in the spread sheet and what you wan't to do with it on the other end. Exporting to csv reduces the file size but it is not a "universal" answer. Compressing the spread sheet into a zip file will reduce the size for transmission without loosing any information.

WOW, this old thread received a big bump. There are some good things to bring out;

File compression is a great point. I would do both, use a CSV (comma seperated variable) file format and some ZIP-type or on the fly compression system.

One time I had to write an EDI (electronic data interchange) application to move spreadsheet type data from a Windows application into an IBM mainframe. CSV was the format I used as it did not have any of the formatting that is embedded in an Excel-type application (fonts, spacing, field types, etc...). All I cared about was the data. I was able to move a significant amount of information across a 300 baud type telephone modem (the same baud rate we can use on HF).

Radio, and particularly HF radio is subject to all sorts of effects like fading and impulse noise that will cause data drop-outs. You want to move your data in as small of packet sizes as you can so your total errors are lower (the error rate will be the same but because it may only be 10-20% of the larger data transaction size your errors will go down significantly).

CSV's are very easy to understand. It is just blocks of data, separated with commas. It would look similar to this; 1,1542,65,Y,N,3,54... Your application knows to put the first value in the first cell, look for the comma and put the next value in the next cell, and so on.

Using an application like ZIP will give you compression but also features like CRC (cyclic redundancy check) error detection so you will know about single bit errors and toss out a corrupted packet as invalid. If you were using something like FEC (forward error correction) that validates each packet by two way communications across the radio link you can also improve reliability.

Remember that we cannot encrypt data but I think that since ZIP is a mostly open standard that anyone can use it might be acceptable to use that (ask the legal eagles on here that question).

---------------------I ran a test, I took one of my Excel spreadsheets from work that has 437 cells (23 rows, 17 columns, some cells up to 13 characters in length, mixture of numbers and text). Here is what it looked like;

To answer Dan's question about size on VHF/UHF, the old saying "size doesn't matter" works.

On VHF, and better yet UHF and SHF, you have a lot more bandwidth than HF. On a HSMM or D-star DD link, an excel file of moderate size would take a few seconds. If you are playing with 1200 baud packet, it's going to take awhile. If you have a 9600 baud packet, a few minutes if the link is good.

On the 500 Hz wide Pactor II/Clover/Winmoor, 35-50 KB of binary file is about as big as I'd go for. Anything larger and you will have quite a long link. Under good conditions that will still take you about 10 minutes to transfer.

If you had Pactor III or Clover 2000/2500 you can cut that to about 5 minutes, but you are now in 2.4 KHZ bandwidth range and paying quite a bit for a modem to operate it.

My contacts in Europe using Pactor IV say that under moderate to good conditions, 50 KB is no problem at all, but unfortunately we can't use that mode, and it costs quite a bit.

My suggestion is that if you need to move files as complicated as Excel or jpgs, you should look to short range UHF links with high speed modes. HF digital modes work best with text which can be easily compressed (50% is not unusual). If you need to move a photo, use SSTV.

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